It is known that if one casts molds made out of synthetic sand (silica and zircon for example, connected by organic resins) without heating the molds first, one obtains castings having a substantial risk of faults (i.e., blisters, micropores).
When heating of the molds is performed, the heating of the core of the mold is generally carried out in an oven with a blowtorch. The mold is then assembled and closed before the casting.
However, the heating produced with a blowtorch is irregular and may not contact all of the surfaces of the mold. Further, after a blowtorch is used for heating of the unassembled mold, the volatile organic products evaporated from the mold during heating can return to the mold in the interval of time necessary for the assembly of the mold before casting. Thus, there is a need for a method and an apparatus for heating a sand mold before casting that contacts the entire surface of the mold and which permits a casting in the mold before the evaporated volatile organic products return to the mold.